Automatic firearm



2 sheets-smet 2 Mez-Z071 waas' M79 G. NORMAN AUTOMAT I C FIREARM FiledJune 5l, 1934 ,mw/ am Sept. 8, 1936.

Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE AUTOMATIC FIREARMApplication `Tune 5, 1934, Serial No. 729,052

7 Claims. (Cl. 42-69) While the invention herein described and claimedis applicable to a great variety of firearms it is particularlyapplicable to automatics (semi-automatic and/or full-automatic) of thetype in which the receiver is' open at the bottom and the frame whichcarries the fire-control mechanism telescopes overl the open bottom fromthe rear, the upper side of the trame being open to permitinterengagement between the recontrol mechanism and the breech-closingmechanism as in the patent to Eickhoif No. 1,437,889, granted December5, 1922.

Objects of the invention are to provide improved means for holding theframe on the receiver and an improved cooperative relationship betweenthe mechanisms carried in the receiver and frame respectively. Moreparticularly the invention affords fire-control mechanism which hasfewer parts, which is more reliable and durable in 4use and which can beassembled and disassembled with greater facility.

`In the aforesaid patent the sear is made in two parts, one of whichengages the bolt and the other of which is actuated by the triggerthrough the medium of a disconnector pivotally mounted on the trigger,and another part called a rocker is arranged to dlsengage thedisconnector from the sear when the bolt advances. A trip is also iprovided to dsengage the disconnector from the sear when the lastcartridge leaves the magazine.

According to the present invention the recontrol mechanism diii'ers fromthe aforesaid construction in one or more of the followingcharacteristics. Instead of forming the sear in two parts it comprises asingle part. The separate rocker for actuating the disconnector in theforward movement of the bolt is eliminated, the disconnector beingactuated directly by the bolt. Instead of pivoting the disconnector onthe trigger it is pivoted on the frame of the gun. The disconnector-ispivoted on the same pin as the trip, thereby eliminating another pivotpin. And instead of the sear being controlled by the trip through themedium of the disconnector the sear is controlled by the disconnectorthrough the medium of the trip. Obviously these characteristics may beused-independently or in vari ous sub-combinations withoutusing them alltogether as in the preferred embodiment. 5o For the purpose of-illustration a typical embodiment of the invention is shown in theaccompanying drawings in which, l,

Fig. 1 is a top plan view ofthe frame of the gun removed from thereceiver; Fig. 2 is a vertical longitudinal section through plunger.

the frame and receiver showing the bolt in retracted position and thefiring mechanism set for semi-automatic operation;

Fig. 3 is a similar view showing the parts set for similar operation butwith the bolt moving 5 forward;

Fig. 4 is a similar view showing the firing mechanism set forfull-automatic operation;

Fig. 5 is a side elevation of the trip-disconnector assembly viewed fromthe opposite side 10 to that shown in Figs. 2, 3 and 4;

Fig. 6 is a side view of the pivot pin for the disconnector and trip;

Fig. 7 is an end view of the pivot pin;

Fig. 8 is a side View of the sear viewed from l5 the same side as inFigs. 2, 3 and 4; and

Fig. 9 is a bottom plan view of the sear.

The particular embodiment of the invention chosen for the purpose ofillustration comprises a receiver IOI, a bolt |08 movable back and forth20 in the receiver and a frame |05 detachably connected to the underside of the receiver by means of inwardlyl extending lips I which slidein grooves in the sides of the receiver IUI, the frame sliding onto thereceiver from the rear and being 25 held in normal position by means ofa catch 2 pivoted in the frame by means of a pin 3 and urged to latchingposition by spring 4. To release the frame from the receiver the catch 2is swung in a clockwise direction by means of a 30 plunger 5 which isprevented from dropping out when the gun is inverted by means of a pin 6extending through a recess 'I in the side of the The mechanism forautomatically locking the bolt in breech-closing position and un- 35locking the bolt in response to the breech pressure may be substantiallylike that disclosed in the aforesaid patent and therefore need not bedescribed herein.

In general the fire-control mechanism, com- 40 prising thesubject-matter of the present invention, comprises a sear 8 pivoted inthe frame at 9, a trigger IIJ pivoted on the pin 3 for swinging the searin a clockwise direction to release the bolt through the medium of atrigger bar Il piv- 45 otally connected to the trigger at I 2 and havinga shoulder I3 for engagement with the depending portion I4 of the sear.To lock the sear in safe position a pin I5 is journaled in the framewith a handle I6 on the left-hand side of theframe to 50 swing the pinthrough The pin I5 has a. cut-away portion I1 underlying the rearwardlyextending portion I8 of the sear so that when the pin is in the positionshown in Figs. 1 to 4 inclusive the sear may be actuated to release the55 180 the'actuation of the sear is blocked by the pin. n

To disengage the trigger bar I I from the sear 8 when the last cartridgeleaves the magazine a trip I9 is'pivoted on the portion 20 of a pin 2lwhich is journaled in the opposite side walls of the frame |05. the tripbeing urged in a counterclockwise direction by a spring 29. 'I'he tripI9 has a rearward portion 22 engaging the forward end of the trigger barI I so that when the trip is rotated in clockwise direction around thepin 2| the shoulder I3 of the trigger bar is moved out of engagementwith the sear to permit the sear to be returned to bolt-holding positionby the sear spring 23 seating in a recess 21 in part 28 o'f the sear.The forward end 24 of the trip I9 extends into the path of a lug 25 onthe magazine follower 26 so that when the last cartridge leaves themagazine thelug 25 swings the trip in clockwise direction to disengagethe trigger bar from the sear.

For semi-automatic operation the gun is provided with a disconnector 30which is pivoted at its forward end on the eccentric portion 4| of thepin 2| and which has at its rearward end a slot 32 into which a pin 33projects from the right-Y hand sideY of the trip I9. Above the slot 32the disconnector is provided with a convex cam surface 34 which, whenthe gun is set for semi-automatic operation, projects into the path ofthe bolt so that when the bolt moves forward it depresses the rearwardend of the disconnector, swinging it in a clockwise direction about thepivot 3|, thereby also swinging the trip I9 in a clockwise direction todisengage the trigger bar from the sear by virtue of the engagement ofthe upper edge of the slot 32 with the pin 33. To move the disconnectorto full-automaticV position the handle 35 of the pivot pin 2| is swungfrom the position shown in Fig. 1 downwardly through 180 to a positionwhere the handle 35 extends rearwardly instead. of forwardly from thepivot pin. Inas-` much as the eccentric portion 3| of the pivot pinextends from the axis of the pin in the same di- -rection as the handle35 the disconnector is moved to the rear when the handle 35 is swungfrom semi-automatic position to full-automatic position, and in thisrearward movement of the disconnector the rear portion of thedisconnector is moved downwardly by engagement of the under side of theslot 32 with the pin 33, thereby removing the convex cam surface A34from the path of the bolt.

'Ihe operation of the rearm is as follows: For semi-automatic operationthe handle 35 of the disconnector pivot pin 2| is set in the positionshown in Figs. 1, 2 and 3. Thus, when thebol is retracted and thetrigger released the parts are `in the position shown in Fig. 2. Whenthe trigger is retracted the bolt, is advanced by the recoil spring 36and when the bolt reaches the position 'shown in Fig. 3 it engages thecam surface 34 to swing the disconnector 30 in a clockwise directionabout the pivot 3|, the upper edge of the slot 32 of the disconnectorpressing downwardly on the pin 33 carried by the trip I9 to swing thetrip I9 in a clockwise direction and this in turn disen,L

boit but when the safety pin l5 is rotated through swung to the rear todepress the rearward end of the disconnector out of the path of the boltas shown in Fig. 4. In this position of the disconnector the trigger baris not disengaged from the sear when the bolt moves forwardly andconsequently the gun will re repeatedly, either until the trigger isreleased or until the lug 25 on the magazine follower engages theforward end of the trip I 9 when the magazine becomes` sear from thebolt, a pivoted trip for disengaging the trigger means from the sear, a.pivoted disconnector responsive to movement of the bolt for disengagingthe trigger means from the sear, and a common pivot pin for said tripand disconnector.

2. An automatic firearm comprising a frame, a bolt,'a sear, triggermeans for disengaging the sear from the bolt, a pivoted trip fordisengaging the trigger means from the sear, a pivoted disconnectorresponsive to movement of the bolt for disengaging the trigger meansfrom the sear, a common pivot pin for said trip and disconnector, thedisconnector being mounted on an eccentric portion of said pin, and ahandle outside the frame for rotating the pin to move the disconnectorout of the path of the bolt for full-automatic operation.

3. An automatic firearm comprising a frame, a bolt, a sear, triggermeans for disengaging the sear from the bolt, a pivoted trip fordisengaging the trigger means from the sear, a pivoted disconnectorresponsive to movement of the bolt ifor disengaging the trigger meansfrom the seat, and a common pivot pin for said trip and disconnector,the disconnector being mounted on an eccentric portion of said pin andhaving a cam- .Iming interconnection with the trip so that when the pinis rotated back and forth the disconnector is moved into and out of thepath of the bolt.

4. An automatic rearm comprising a frame. a magazine, a bolt, a sear,trigger means for disengaging the sear from the bolt, a trip pivoted onsaid frame for disengaging the trigger means from the sear, and adisconnector respt-nsive to movement of the bolt for actuating saidtrip, said trip having an integral portion actuated directly by themagazine when the last cartridge leaves the magazine.

5. An automatic rearm comprising a frame, a magazine, a bolt, a sear,trigger means for disengaging the sear from the bolt, a pivoted trip fordisengaging the trigger means from the sear, a pivoted disconnectorresponsive to movement of the bolt for causing the trip to disengage thetrigger means from the sear, a common pivot pin for said trip anddisconnector, and means for actuating the trip when the magazine visemptied:

6. An auto'matic firearm comprising a frame, a magazine, a bolt, a sear,trigger means for disl engaging the sear from the bolt, a pivoted tripfor disengaging the trigger means from the sear, a pivoted disconnectorresponsive to movement of the bolt for disengaging the trigger meansfrom the sear, a common pivot pin for said trip and disconnector, thedisconnector being mounted on an eccentric portion of said pin, and a ihandle outside the frame for rotating the pin to move the disconnectorout of the path of the bolt for full-automatic operation. a common pivotpin for said trip and disconnector. and means for actuating the tripwhen the magazine is emptied.

7. An automatic firearm comprising a frame. a magazine. a bolt, a sear,trigger means for disengaging the sear from the bolt, a pivoted trip fordisensains the trigger means from the sear, a pivoted disconnectorresponsive to movement of the bolt for disengaging the trigger meansfrom the sear, and a common pivot pin for said trip and disconnector.said trip having a portion actuated by the magazine when the lastcartridge leaves the magazine.

GEORGE NORMAN.

